ShapeConverters.cs

using System.Globalization;
using Microsoft.Maui.Controls.Shapes;


namespace Maui.Controls.Sample;

public class StringToPointCollectionConverter : IValueConverter
{
	public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
	{
		if (value is string pointsString && !string.IsNullOrWhiteSpace(pointsString))
		{
			var points = new PointCollection();
			var pointPairs = pointsString.Split(' ');

			foreach (var pointPair in pointPairs)
			{
				var coords = pointPair.Split(',');
				if (coords.Length == 2 &&
					double.TryParse(coords[0], out double x) &&
					double.TryParse(coords[1], out double y))
				{
					points.Add(new Point(x, y));
				}
			}
			return points;
		}
		return new PointCollection();
	}

	public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
	{
		if (value is PointCollection points)
		{
			var pointStrings = new List<string>();
			foreach (Point point in points)
			{
				pointStrings.Add($"{point.X},{point.Y}");
			}
			return string.Join(" ", pointStrings);
		}
		return string.Empty;
	}
}

public class StringToPathGeometryConverter : IValueConverter
{
	public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
	{
		if (value is string pathData && !string.IsNullOrWhiteSpace(pathData))
		{
			try
			{
				return (Geometry)new PathGeometryConverter().ConvertFromInvariantString(pathData);
			}
			catch
			{
				// Return a simple default path if parsing fails
				return (Geometry)new PathGeometryConverter().ConvertFromInvariantString("M 10,100 L 100,100");
			}
		}
		return (Geometry)new PathGeometryConverter().ConvertFromInvariantString("M 10,100 L 100,100");
	}

	public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
	{
		return value?.ToString() ?? string.Empty;
	}
}

public class StringToDoubleCollectionConverter : IValueConverter
{
	public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
	{
		if (value is string dashArray && !string.IsNullOrWhiteSpace(dashArray))
		{
			var collection = new DoubleCollection();
			var values = dashArray.Split(',');

			foreach (var val in values)
			{
				if (double.TryParse(val.Trim(), out double dashValue))
				{
					collection.Add(dashValue);
				}
			}
			return collection;
		}
		return new DoubleCollection();
	}

	public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
	{
		if (value is DoubleCollection collection)
		{
			return string.Join(",", collection);
		}
		return string.Empty;
	}
}